package tests

import (
	"context"
	"io"
	"log"
	"os"
	"path/filepath"
	"testing"

	"Moonshark/routers"
	"Moonshark/runner"
	"Moonshark/utils/logger"
)

// setupTestEnv initializes test components and returns cleanup function
func setupTestEnv(b *testing.B) (*routers.LuaRouter, *runner.Runner, func()) {
	// Completely silence logging during benchmarks
	logger.InitGlobalLogger(false, false)

	// Redirect standard logger output to discard
	log.SetOutput(io.Discard)

	// Store original stderr to restore later
	originalStderr := os.Stderr
	devNull, _ := os.Open(os.DevNull)
	os.Stderr = devNull

	// Create temp directories
	tempDir, err := os.MkdirTemp("", "moonshark-bench")
	if err != nil {
		b.Fatalf("Failed to create temp dir: %v", err)
	}

	// Rest of the function remains the same...
	routesDir := filepath.Join(tempDir, "routes")
	staticDir := filepath.Join(tempDir, "static")
	libsDir := filepath.Join(tempDir, "libs")
	dataDir := filepath.Join(tempDir, "data")
	fsDir := filepath.Join(tempDir, "fs")

	os.MkdirAll(routesDir, 0755)
	os.MkdirAll(staticDir, 0755)
	os.MkdirAll(libsDir, 0755)
	os.MkdirAll(dataDir, 0755)
	os.MkdirAll(fsDir, 0755)

	// Create test routes
	createTestRoutes(routesDir)

	// Initialize router
	luaRouter, err := routers.NewLuaRouter(routesDir)
	if err != nil {
		b.Fatalf("Failed to create router: %v", err)
	}

	// Initialize runner
	luaRunner, err := runner.NewRunner(
		runner.WithPoolSize(4),
		runner.WithLibDirs(libsDir),
		runner.WithDataDir(dataDir),
		runner.WithFsDir(fsDir),
	)
	if err != nil {
		b.Fatalf("Failed to create runner: %v", err)
	}

	// Return cleanup function that restores stderr
	cleanup := func() {
		luaRunner.Close()
		os.RemoveAll(tempDir)
		os.Stderr = originalStderr
		devNull.Close()
	}

	return luaRouter, luaRunner, cleanup
}

// createTestRoutes creates test Lua scripts for benchmarking
func createTestRoutes(routesDir string) {
	// Simple GET endpoint
	getCode := []byte(`return "Hello, World!"`)
	os.WriteFile(filepath.Join(routesDir, "GET_hello.lua"), getCode, 0644)

	// POST endpoint with form handling
	postCode := []byte(`
		local data = ctx.form or {}
		return "Received: " .. (data.message or "no message")
	`)
	os.WriteFile(filepath.Join(routesDir, "POST_hello.lua"), postCode, 0644)

	// Computationally intensive endpoint
	complexCode := []byte(`
		local result = {}
		for i = 1, 1000 do
			table.insert(result, i * i)
		end
		return "Calculated " .. #result .. " squared numbers"
	`)
	os.WriteFile(filepath.Join(routesDir, "GET_complex.lua"), complexCode, 0644)
}

// BenchmarkRouterLookup tests route lookup performance
func BenchmarkRouterLookup(b *testing.B) {
	luaRouter, _, cleanup := setupTestEnv(b)
	defer cleanup()

	method := "GET"
	path := "/hello"
	params := &routers.Params{}

	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		_, _, _, _ = luaRouter.GetRouteInfo(method, path, params)
	}
}

// BenchmarkSimpleLuaExecution tests execution of a simple Lua script
func BenchmarkSimpleLuaExecution(b *testing.B) {
	luaRouter, luaRunner, cleanup := setupTestEnv(b)
	defer cleanup()

	method := "GET"
	path := "/hello"
	params := &routers.Params{}
	bytecode, scriptPath, _, _ := luaRouter.GetRouteInfo(method, path, params)

	ctx := runner.NewContext()
	defer ctx.Release()

	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		_, _ = luaRunner.Run(bytecode, ctx, scriptPath)
	}
}

// BenchmarkComplexLuaExecution tests execution of a computation-heavy script
func BenchmarkComplexLuaExecution(b *testing.B) {
	luaRouter, luaRunner, cleanup := setupTestEnv(b)
	defer cleanup()

	method := "GET"
	path := "/complex"
	params := &routers.Params{}
	bytecode, scriptPath, _, _ := luaRouter.GetRouteInfo(method, path, params)

	ctx := runner.NewContext()
	defer ctx.Release()

	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		_, _ = luaRunner.Run(bytecode, ctx, scriptPath)
	}
}

// BenchmarkGetEndpoint tests end-to-end processing for GET endpoint
func BenchmarkGetEndpoint(b *testing.B) {
	luaRouter, luaRunner, cleanup := setupTestEnv(b)
	defer cleanup()

	method := "GET"
	path := "/hello"
	params := &routers.Params{}

	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		// Route lookup
		bytecode, scriptPath, _, _ := luaRouter.GetRouteInfo(method, path, params)

		// Context setup
		ctx := runner.NewContext()

		// Script execution
		_, _ = luaRunner.Run(bytecode, ctx, scriptPath)

		// Cleanup
		ctx.Release()
	}
}

// BenchmarkPostEndpoint tests end-to-end processing for POST endpoint
func BenchmarkPostEndpoint(b *testing.B) {
	luaRouter, luaRunner, cleanup := setupTestEnv(b)
	defer cleanup()

	method := "POST"
	path := "/hello"
	params := &routers.Params{}

	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		// Route lookup
		bytecode, scriptPath, _, _ := luaRouter.GetRouteInfo(method, path, params)

		// Context setup with form data
		ctx := runner.NewContext()
		ctx.Set("form", map[string]any{
			"message": "Hello from benchmark test",
		})

		// Script execution
		_, _ = luaRunner.Run(bytecode, ctx, scriptPath)

		// Cleanup
		ctx.Release()
	}
}

// BenchmarkConcurrentExecution tests parallel execution performance
func BenchmarkConcurrentExecution(b *testing.B) {
	luaRouter, luaRunner, cleanup := setupTestEnv(b)
	defer cleanup()

	method := "GET"
	path := "/hello"
	params := &routers.Params{}
	bytecode, scriptPath, _, _ := luaRouter.GetRouteInfo(method, path, params)

	b.ResetTimer()
	b.RunParallel(func(pb *testing.PB) {
		for pb.Next() {
			ctx := runner.NewContext()
			_, _ = luaRunner.Run(bytecode, ctx, scriptPath)
			ctx.Release()
		}
	})
}

// BenchmarkConcurrentComplexExecution tests parallel execution of intensive scripts
func BenchmarkConcurrentComplexExecution(b *testing.B) {
	luaRouter, luaRunner, cleanup := setupTestEnv(b)
	defer cleanup()

	method := "GET"
	path := "/complex"
	params := &routers.Params{}
	bytecode, scriptPath, _, _ := luaRouter.GetRouteInfo(method, path, params)

	b.ResetTimer()
	b.RunParallel(func(pb *testing.PB) {
		for pb.Next() {
			ctx := runner.NewContext()
			_, _ = luaRunner.Run(bytecode, ctx, scriptPath)
			ctx.Release()
		}
	})
}

// BenchmarkRouteCompilation tests the performance of route compilation
func BenchmarkRouteCompilation(b *testing.B) {
	tempDir, err := os.MkdirTemp("", "moonshark-compile")
	if err != nil {
		b.Fatalf("Failed to create temp dir: %v", err)
	}
	defer os.RemoveAll(tempDir)

	routesDir := filepath.Join(tempDir, "routes")
	os.MkdirAll(routesDir, 0755)

	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		b.StopTimer()
		os.RemoveAll(routesDir)
		os.MkdirAll(routesDir, 0755)
		createTestRoutes(routesDir)
		b.StartTimer()

		// Creating router triggers compilation
		_, _ = routers.NewLuaRouter(routesDir)
	}
}

// BenchmarkContextCreation measures the cost of creating execution contexts
func BenchmarkContextCreation(b *testing.B) {
	for i := 0; i < b.N; i++ {
		ctx := runner.NewContext()
		ctx.Release()
	}
}

// BenchmarkContextWithData measures context creation with realistic data
func BenchmarkContextWithData(b *testing.B) {
	for i := 0; i < b.N; i++ {
		ctx := runner.NewContext()
		ctx.Set("method", "POST")
		ctx.Set("path", "/api/users")
		ctx.Set("host", "example.com")
		ctx.Set("params", map[string]any{"id": "123"})
		ctx.Set("form", map[string]any{
			"username": "testuser",
			"email":    "user@example.com",
			"active":   true,
		})
		ctx.Release()
	}
}

// BenchmarkRunnerExecute tests the runner's Execute method with timeout
func BenchmarkRunnerExecute(b *testing.B) {
	luaRouter, luaRunner, cleanup := setupTestEnv(b)
	defer cleanup()

	method := "GET"
	path := "/hello"
	params := &routers.Params{}
	bytecode, scriptPath, _, _ := luaRouter.GetRouteInfo(method, path, params)

	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		ctx := runner.NewContext()
		_, _ = luaRunner.Execute(context.Background(), bytecode, ctx, scriptPath)
		ctx.Release()
	}
}